A brush plate of a brush motor typically includes brushes, a plurality of other electrical components, and conductors for supplying power to the brushes and electrical components. Overheat protection devices may be connected between the conductors and the brushes, or between the conductors and other electrical components to prevent overly large currents from flowing through the motor which would damage the motor. In a typical example of such a brush plate, the overheat protection device includes a resilient strip as shown in FIG. 6. One end of the resilient strip is connected to the circuit by a solder joint. When the current is overly large, or the heat inside the motor is too high, the solder of the solder joint melts, which allows the resilient strip to pop up thus breaking the circuit. However, in this type of overheat protection device, the solder joint has a poor reliability. The solder may release the strip due to shock or corrosion during use, which would cause the motor to malfunction. In addition, the various solder materials used have a narrow melting range, which results in such devices only being suitable for a limited range of operating conditions.
Hence, there is a desire for a brush plate with an improved overheat protection function for a brush motor.